Molecular weights and molecular weight distributions of irradiated cellulose fibers by gel permeation chromatography. [. gamma. radiation]

Journal Article · Tue Jun 01 04:00:00 EDT 1976 · J. Appl. Polym. Sci.; (United States)

DOI:https://doi.org/10.1002/app.1976.070200626· OSTI ID:7270904

Kusama, Y ^[1]; Kageyama, E; Shimada, M; Nakamura, Y

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1. Japan Atomic Energy Research Inst., Takasaki

Radiation degradation of cellulose fibers was investigated by gel permeation chromatography (GPC). Scoured cotton of Mexican variety (cellulose I), Polynosic rayon (cellulose II), and their microcrystalline celluloses obtained by hydrolysis of the original fibers were irradiated by Co-60 ..gamma..-rays under vacuum or humid conditions. The irradiated samples were then nitrated under nondegradative conditions. The molecular weights and molecular weight distributions were measured by GPC using tetrahydrofuran as solvent. The relationship between molecular weight and elution count was obtained with cellulose trinitrate standards fractionated by preparative GPC. The degree of polymerization of the fibers decreased with increasing irradiation dose, but their microcrystalline celluloses were only slightly degraded by irradiation, especially in microcrystalline cellulose from cellulose I. Degradation of the fibers irradiated under humid conditions was less than that irradiated under vacuum. It was found that the G-values for main-chain scission for the irradiated cellulose I, cellulose II, microcrystalline cellulose I, and microcrystalline cellulose II were 2.8, 2.9, less than 1, and 2.9, respectively, but the G-value for main-chain scission for the irradiated cellulose II was increased to 11.2 at irradiation doses above 3 Mrad. Consequently, it is inferred that cellulose molecules in the amorphous regions are degraded more readily, and the well-aligned molecules in crystalline regions are not as easily degraded by irradiation.

• OSTI ID: 7270904
• Journal Information: J. Appl. Polym. Sci.; (United States), Journal Name: J. Appl. Polym. Sci.; (United States) Vol. 20:6; ISSN JAPNA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360406* -- Materials-- Polymers & Plastics-- Radiation Effects-- (-1987)
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600 -- Radiation Chemistry
CARBOHYDRATES
CELLULOSE
CHEMICAL RADIATION EFFECTS
CHEMISTRY
CHROMATOGRAPHY
DOSES
ELECTROMAGNETIC RADIATION
FIBERS
G VALUE
GAMMA RADIATION
HUMIDITY
IONIZING RADIATIONS
MOLECULAR WEIGHT
ORGANIC COMPOUNDS
POLYSACCHARIDES
RADIATION CHEMISTRY
RADIATION DOSES
RADIATION EFFECTS
RADIATIONS
SACCHARIDES
SEPARATION PROCESSES